3 visuals for webpage

This code will help produce the three visuals that are going to be a part of each equity tracker indicator webpage: regional map (tract level) of most recent data, chart of the most recent data, chart of trends over time.

If the indicator is available through a tract-level data set. Getting the data to a workable version may require some data transformation. To explore, clean, transform, and generate a final data set, please use the data-gen-tract-template. This script will generate an .rda for the map and an .rda for the charts. These data sets will be loaded in before the data visualization code.

Indicator Explanation

Average percentage of tree canopy by census tract. Understanding tree canopy coverage can help us understand which communities are disproportionately impacted by less tree canopy. Reduced tree canopy can impact quality of life in various ways including leading to warmer temperatures and decreased access to open space/parks.

Calculations were made using original data from MRLC and applying ArcGIS Zonal Statistics as Table tool to calculate the average percentage of canopy cover per census tract.

1. Map of most recent data

To map data in this form, there should be a value corresponding to each census tract. Depending on the year or source of the data, this could be about 700 rows for data at the 2010 census tract resolution, or about 900 rows for data at the 2020 census tract resolution.

Create Visual

Source(s): USDA Forest Service and MRLC, Tree Canopy, 2021; U.S. Census Bureau, Geography Division 2020 TIGER/Line Shapefiles


Data call outs

  1. 54%: The region’s average tree canopy coverage per census tract in 2021
  2. 73%: census tract with the highest average percentage of tree canopy in 2021
  3. 1%: census tract with the lowest average percentage of tree canopy in 2021


Insights & Analysis

  • The census tracts with the highest average tree canopy cover includes three census tracts in King County that include the tract east of Enumclaw heading into the foothills of the Cascades (73%), the tract with the Cedar River Watershed (72%), the tract with Tiger Mountain (70%), and in Snohomish County the tract with Mt. Pilchuck (68%)
  • The census tracts with the lowest average tree canopy cover are in King County and include South Lake Union (1%), the two tracts that make up downtown Seattle (both 1%), and the tract with Boeing Field (2%)
  • King County has the highest average tree canopy cover (55.9%), followed by Snohomish (55.8%), Kitsap (54.1%), and Pierce (50.6%)



2. Facet of most recent data

Create Visual

Tree Canopy Cover by Community

Average percent of area with tree canopy

USDA Forest Service and MRLC, Tree Canopy, 2021; U.S. Census Bureau, 2016-2021 American Community Survey 5-Year Estimates, Tables B02001, C17002, B22010, B11005, B11007, C16002


Data call outs

  1. 2x: As a region, communities with low concentrations of households with lower income have over twice the canopy cover as communities with high concentrations
  2. 2x: As a region, communities with low concentrations of people of color have over twice the canopy cover as communities with high concentrations
  3. 2x: As a region, communities with low concentrations of people of households with limited English proficiency have over twice the canopy cover as communities with high concentrations


Insights & Analysis

  • Communities with the highest concentration of people of color, households with lower income, households with limited English proficiency, and youth under 18 are most disproportionately impacted by lower average tree canopy cover
  • The counties with the largest gap between low and high concentrations of people of color are King and Snohomish counties
  • The counties with the largest gap between low and high concentrations of households with lower income are King and Pierce counties




3. Facet of trend data

Create Visual

Tree Canopy Cover Trend by Community

Average percent of area with tree canopy, in 5-year spans between 2011 and 2021

USDA Forest Service and MRLC, Tree Canopy, 2011, 2016, 2021; U.S. Census Bureau, 2007-2011, 2012-2016, 2017-2021 American Community Survey 5-Year Estimates, Tables B02001, C17002, B22010, B11005, B11007, C16002

Data call outs

  1. 50% decrease: As a region since 2016, communities with high concentrations of households with lower income have seen over a 50% decrease in average tree canopy coverage
  2. 10%: As a region, communities with high concentrations of households with youth under 18 have seen a 10% decrease in average tree canopy coverage since 2011
  3. 20%: Kitsap County has seen a 20% increase in tree canopy coverage for households with limited English proficiency since 2011

Insights & Analysis

  • As a region, communities with the highest and lowest concentrations of people of color have seen consistent average tree canopy coverage from 2011 to 2021
  • As a region, communities with high concentrations of households with limited English proficiency have seen consistent average tree canopy coverage from 2011 to 2021
  • Pierce County has seen the largest increase in the gap between the highest and lowest concentrations for households with lower income between 2011 and 2021



Transfer files

Copy files from Github > Y drive

Copy files from Y drive > website folder

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